1. Field of Invention:
This invention relates generally to baking pan assemblies, and more particularly to a dual-purpose assembly usable in both conventional ovens and in microwave ovens, which assembly may be disassembled after baking is completed to expose the food product without disturbing its structure.
2. Status of Prior Art
In making cakes, particularly cheesecakes, and other baked products, the utensil used for this purpose in the case of cheesecakes usually has a cylindrical form and is made of a material appropriate to the type of heating oven used. Since the present invention deals with a baking pan assembly usable in either a conventional hot air oven or in a microwave oven, the various pan requirements for these ovens will first be considered.
When a food product is baked in a conventional oven having electrical heating elements or a gas burner, the atmosphere in the oven is heated to a high temperature, and this heat energy is transferred to the surface of the food product by convection, from which surface the heat is transferred by conduction to the body of the food product. Hence, in this instance the baking pan, which may be of metallic construction, such as stainless steel or aluminum, or of non-metallic construction, such as glass or ceramics, must be capable of withstanding the high temperatures to which both the pan and the food therein are exposed.
In a microwave oven, food is internally heated by subjecting it to electromagnetic wave energy in the microwave spectrum. The frequencies most often used for this purpose are in the bands such as 2.45 GHz reserved for industrial, scientific and medical purposes. In a typical microwave oven, microwave energy generated by a magnetron is directed by a wave guide to food contained in a pan of electrically-insulating or dielectric material, so that the energy is absorbed by the food and not by the pan which remains unaffected thereby.
A pan made of metal cannot be used in a microwave oven, nor a non-metallic material having poor dielectric properties, such as one containing carbon. Metals reflect microwave energy and therefore shield the food therein from microwave energy; whereas materials having poor dielectric properties absorb microwave energy and therefore become heated thereby.
Hence, the first requirement for a baking pan to be used either in a conventional oven or in a microwave oven is that it be made of a material acceptable to both types of ovens and that this material not be brittle. Thus, certain types of tempered glass are suitable for a dual-purpose baking pan.
The second requirement has to do with the fragile nature of the baked food product. If one bakes, say, a cheesecake in a conventional pan, it then becomes difficult after baking to remove the cake from the pan without disrupting its structure. Thus, a pan molded of glass is not suitable. To solve this problem, various forms of sectioned pans have been proposed to facilitate the detachment therefrom from the food after baking is completed and the pan is withdrawn from the oven.
Thus, the Crosby U.S. Pat. No. 1,191,672 discloses a pie pan formed by a pair of complementary half sections that are joined together by latching elements so that one can detach the pan from the baked pie without disturbing the pie structure. Similar sectioned pans are shown in the Neumeister U.S. Pat. No. 1,397,775, and in the Hurst U.S. Pat. No. 1,879,268.
The Young U.S. Pat. No. 2,030,344 shows a pan having a cylindrical shield that is split and is provided with a latch to provide a tight joint around the rim of the pan. This cylindrical shield acts as a guard to prevent juice from running over the sides of the pan during baking. The Moyen U.S. Pat. No. 2,222,512 and the Conry U.S. Pat. No. 1,734,328 also show removable ring attachments for pie pans to prevent runover of juice from the pan into the baking oven.
None of these prior art baking pan assemblies which are of metallic construction is suitable for baked products such as cheesecake for both microwave and conventional ovens. Moreover, none of the prior art pans can be completely dismantled to permit thorough cleaning of all of its parts.